IT WAS THE LARGEST EXPERIMENT WE HAVE EVER PERFORMED. IT ... SIX H...

29. - BO DE KIEM TRA TRAC NGHIEM TIENG ANH T3 5231
BO DE KIEM TRA TRAC NGHIEM TIENG ANH T3 5231

29. It was the largest experiment we have ever performed. It ... six

hours.

a. ended

b. finished

c. was

d. lasted

→d